The ablative heat shield used by the Spirit and Opportunity rovers was a blend of cork wood and silica spheres [1]. Also, the reentry vehicles for the Chinese

The ablative heat shield used by the Spirit and Opportunity rovers was a blend of cork wood and silica spheres [1]. Also, the reentry vehicles for the Chinese FSW reconnaissance satellites used heat shields made from Oak. [1] http://marsrover.nasa.gov/mission/spacecraft_edl_aeroshell.html http://marsrover.nasa.gov/mission/spacecraft_edl_aeroshell.h...